// 1像素边框
border-top-retina(color=$-default-gray-border-color, width=1px)
    position relative

    &:before
        content ""
        position absolute
        left 0
        top 0
        height width
        width 100%
        transform scaleY(0.5)
        transform-origin 0 0
        background color

border-bottom-retina(color=$-default-gray-border-color, width=1px)
    position relative

    &:after
        content ""
        position absolute
        left 0
        top 0
        height width
        width 100%
        transform scaleY(0.5)
        transform-origin 0 0
        background color
        top auto
        bottom 0
        transform-origin 0 100%
